Clutch mechanism



Jan. 24, 1939. A L. J, CAMBELL CLUTCH MECHANI SM Filed 591313.29, 1937 INV ENT OR. 5U/V Z4/|4555@ if. M

' ATTORNEY.

Patented dan. 24, 193g" A 'i UNITED STATES PATENT OFFICE 2,144,64

CLUTCH MECEANISM Leon J. Campbell, Chicago, Ill., assigner to Campbell-Buchanan Corporation, Chicago, Ill., a corporation of Illinois Y Application september 29, 1937, serial No. 166,260

` 2 7 Claims. (Cl. 192-53) This invention relates to clutch mechanisms parts in elevation, of a synchronizing clutch deand more particularly to synchronizing clutches vice of my invention in an automotive change for automotive change speed transmissions. speed transmission;

.These clutch assemblies comprise in general a Fig. 2 is a transverse sectional view taken on 5 frictlonal clutch unit and a positive clutch unit, the indirect line 2--2 of Fig. l; 5

the latter being employed to directly connect the Fig. 3 is an elevational view of the carrier eleelements with respect to which the clutch units ment to be hereinafter' described; and are associated following their synchronization by Fig. 4 is a fragmentary sectional view showing the frictional clutch. w a'detail as to the spring disc to be later described. l0 In accordance with my invention, the opposed In the drawing, I, 2 indicate the alined driving 10 annular inclined friotionalclutch surfaces of the y and driven shafts of an automotive change speedv co-operating clutch members of Vthe frictional transmission assembly. The shaft l leads from clutch unit are disposed at different angles to the master clutch (not shown) of the vehicle and the axis of rotation of the alined driving andv extends into the transmission case through its 1.; driven elements which said clutch members sefront wall 3, being journaled in said wall in an 15 lectively engage.A One of these surfaces is at a anti-friction bearing 4, as shown. greater or steeper angle or incline to said axis A gear 5 is integral with or otherwise rigidly than the other clutch surface, thus enabling the fixed to the shaft l within the transmission case surface of the lesser angle to be disposed within and said gear is in constant mesh with a gear 6 range most effective for securing-'a driving con- .on a lay shaft (not shown) as in devices of this 20 nection for the clutch members when the unit is general character. The lay shaft is journaled engaged. On the other hand the clutch surface below the alined driving and driven shafts I, 2 of the greater angle may be disposed within the and provides a support for the other lay shaft range required to aiord the requisite' slippage in gears (not shown) spooled to each other and to 7 the unit to gradually pick up a load and a quick the gear 6 for rotation in unison. The lay shaft 25 release so that the positive clutch unit may be gears are for the second, third, and reverse speeds, engaged without loss of synchronism between the respectively, ofthe transmission. The portion of elements as established by the frictional clutch. the shaft 'I at the gear 5 is made hollow and is- This arrangement provides an effectively acting fitted with a roller bearing 1 to receive and sup- ;m clutch construction and one which may be enport the adjacent reduced end of the shaft 2, as 430 gaged and disengaged without noise, shock or jar. shown.

In order that the frictional clutchv surfaces The inner portion .of the shaft I beyond the which are arranged at different angles may lfuncgear 5 is splined, as at 8, 8. The adjacent portion in the operation of the frictional. clutch unit tion ofthe shaft 2 is also splined, as at 9, 9. The

Y; for establishing a driving connection, I provide splined portions of the two shafts have the same 35 meansv between -said surfaces of Va character to diameter and the splines 8, 9 on theI two shafts I frictionally engage them, said means also having are similar, so that when the shafts are synchrosurfaces, complementary to the clutch surfaces nized, the clutch member Ill of the positive clutch of the frictional clutch units. e Y may be slid part way onto the shaft -2 for posi- The means referred to may 'take any suitable tively connecting the two shafts for a high spee 40 form, anarrangement of clutch blocks being proor direct `connection between them. vided in the instant disclosure. These blocks, in 'I'he clutch member I0 is in the form of a sleeve accordance with my invention, vare supported besurrounding the shaft I and is provided with intween the opposed frictional clutch surfaces re.- ternal teeth Il to engage the splines 8, 9 on the .f ferred to by a suitable carrier which may be in the two shafts. Normally, the clutch member I0 is 45 form of a ring having openings to accommodate supported by the shaft l, at which time the shafts the blocks. The blocks are tightened between the may be wholly disconnected, or may be connected frictional clutch surfaces mentioned on closing for synchronization by the frictional clutch unit the frictional clutch unit the members of Awhich to be presently described. When the two shafts 50 may be relativelyshiftable with respect to each are .connected for direct drive, the sleeve Il is 50 other as will hereinafter appear. A slid partially onto the shaft 2, thereby bridging The invention consists' further in the features the joint between the tWO Shafts and engaging hereinafter described and claimed. j e the splines of both of them as indicated in dotted In the accompanying drawing i v lines in Fig. 1. i Fig. 1 isa longitudinal sectional view, with The frictional clutch unit comprises two co- 55 operating cone clutch members I2, I3 on the shafts I and 2, respectively. The member I2 is rigidly fixed to the gear 5 as by screws Il, and has a laterally extending annular portion I 5 surrounding the co-operating part I6 of the clutch member I3. In accordance with my invention'. the opposed annular surfaces I1, I8 of the clutch parts l5 and I6 are inclined to the axis of rotation of the shafts I, 2 at different angles, the angularity of the surface I1 being of a lesser degreeV than that of the surface I8. In the embodiment,

shown, the surface I1 is at an angle of approximately 5 to the axis referred to, while the surface I8 is at an angle of approximately '1 to said axis. 'I'his provides the clutch member I3 with a steeper taper or incline than the clutch member I2 for the purpose to presently appear. These tapers are disposed with their apices on the same side of the clutch members I2, I3, as will be seenv from Fig. 1.

Arranged between the tapers is a ring-like carrier I8 provided with a plurality of displaceable clutch blocks 2U, 20 of the desired wear resistant metal. The carrier ring I8 is retained in place between the tapers by a splitl stop ring 2l at the outer edge of the carrier as shown. The stop ring' 2| is carried by the clutch member I2 in a groove 22 in its inner surface I1. A spring disc 23 is fitted adjacent the inner side of the radial body portion 24 of the clutch member I2 and engages the inner edge of the carrier I9 to normally urge it in a direction toward the stop ring 2|. In the embodiment shown, the spring disc 23 has its outer periphery formed with divergent fingers 25 to respectively engage against the inner edge of the carrier I9 and the opposed wall of the clutch body I2 as shown in Fig. 4. Any other form of spring means may be employed as desired to yieldingly urge the carrier I8 toward the stop 2l. Also, the clutch member I2 may be riveted to the gear 5, if desired.

The diameter of the carrier I9 is such that it is out of contact at all times with the tapered surfaces I1, I8 of the clutch members I2 and I3 as shown in the drawing. The clutch blocks 2II are disposed in openings 26 in the carrier I9 and are forced by the clutch member I3 against the clutch member I2 when connecting the shafts l, 2 through said members. The blocks 28 are circumferentially spaced about the carrier as indicated in Fig. 2, and have their outer surfaces 21 :inclined complementary to the tapered surface I1 of the clutch member I2 and their inner surfaces 28 inclined complementary to the tapered surface I8 of the clutch member I3. 'I'he blocks 20 fit sufliciently loose in the openings 26 so .that the blocks may be readily and easily forced against the clutch member I2 without hinderance by the carrier I3. 'I'he blocks 28 are prevented from dropping out of the openings 28 by having a tapered or other interconnection between the carrier and the blocks.

The clutch member I3 is supported by the driven shaft 2, having internal teeth 29 in mesh with the splines `8 of said shaft as shown. The

lclutch member I3 is moved or shifted toward and The portion IB of the clutch member I 3 surrounds the positive clutch element Il as shown in Fig. 1. The portion IE andthe body of the clutch member I3 provide a chamber or recess 32 for the clutch element III, the latter being Yrotatably retained in said recess by a split holdbefore connection by the positive clutch. It is to be of course understood that the frictional clutch is released before the positive clutch is thrown in. With my invention, as will presently appear, the difference in angularity with respect to the clutch surfaces I1, I8 provides for a quick release of frictional clutch unit on being disengaged, and the positive clutch unit may be engaged without loss of synchronism as established between the shafts by the frictional clutch. Hence, the positive clutch connection may beV made quickly and easily and without noise, shock or jar as the teeth II of the clutch element Il are moved into the spaces between the splines 3 on the shaft 2. There is no ygrinding action between the two sets of teeth as the shafts are synchronized when one set of teeth are meshed with the other, it being understood that there is a full complement of teeth about the circumference of each clutch member.

The surface I8 of the greater angle or inclination provides for the quick release between the clutch members. This surface is not employed to afford the driving connection between the ments for the clutch members to gradually and easily pick up a load as the clutch is engaged.

The surface I1 on the other hand provides the vdriving connection for the clutch members I2 and I3 and not being concerned with the quick release of the clutch or the slippage factors thereof may be given the lesser angle or inclination required to afford the most effective driving and grabbing connection for the clutch. Manifestly, theclutch of my invention is highly effective because the opposed annular clutch surfaces I1, I8 are confined to their respective duties as herein stated, and are not required vto afford both a driving connection and the slippage factors for the clutch as in those clutch constructions wherein the opposed annular frictional clutch surfaces are complementary and directly engaged. VI have found in practice for automotive change speed transmissions in particular, that a 5 angle for the surface I1 gives an effective driving connection, while a '1 angle for the surface-I8. gives a quick release and the slippage necessaryfor the clutch. I do notwish to be limited to these particular angles, as my inven.- tion contemplates any differential angular arrangement as may be necessary for the particular clutch construction with respect'to which my'invention may be employed.

The connection betweenl the clutch members I2 and I3 is of course effected through the clutch As the clutch-unit is engaged on shift- 4ing the clutch member I3 toward the clutch blocks 2l.

" vmember I2, the annular abutment or shoulder gio.

. member I3.

-I3a on the shiftable clutch member I3 contacts thev outer edge of the carrier-ring I Slbefore the AmemberIS actson the blocks-20. This action centers the carrier and its blocks between the clutch surfaces I'I and I8 and the carrier is also picked up and rotated by the. rotating clutch This throwsv the blocks into contact v withthesurface I1 of the lesser angle and a con- 'tinued inward movement of the clutch member I3'engages its surface I8 with the blocks and y forces them against the surface II.` The outer member.

surfaces 2'I of the blocks having the same taper as the lsurface I'I affords a driving connection between the clutch member I2 and the blocks before such 'connection is transmitted to the clutch torque strains are overcome, and the driving connection afforded by the surface I1 of the lesser angle is transmitted to Vthe clutch member I3 as the latter surface I'I.

The greater angle (surface I8) has the further I advantage of providing a greater leverage for pressing the blocks 20 against the clutch mem-l ber. I2. These blocks have grooves 35, 35 in their inner land outer surfaces to scrape or remove lubricant from the clutch surfaces I1, I8 and thus render them sufficiently dry for the. frictional clutch to engage. 'I'hese grooves extend axially of the shafts I, 2 and are essential because the transmission mechanism runs in oil or greasel and the clutch parts are made of metal providing a metal to metal contact between them. While the positive clutch element II) is shifted into clutching engagement with the shaft 2 on beingout of driving engagement with the clutch surface I'I. The extent-to which the clutch element I is shifted to positively connect the two shafts isshown in dotted lines in Fig. 1 and 4in full lines in Fig. 4. It will be noted `that the element Ill in this position is out of contact with clutch blocks 20. The frictional clutch is also disengaged at this time. In a `transmission assembly of the characte described' two clutch assemblies asdepicted in Fig. 1 are employed. One assembly is fordirect drive or high speed as shown in Fig. 1, and

the other assembly is for the second or inter-k mediate speed as shown in myv` Patent No. granted December 8, 1934. Both clutch assemblies would be alike in construc-v tion and operation, except that the assembly at the intermediate speed would have its parts reversed, being arranged, however, with the xed clutch member I2 on 'the driving element, and the shiftable clutch member I3 on the driven e element.

The details of construction and arrangement oi parts shown and described may be variously lchanged and modified without departing from the spirit and scope of my invention, except as pointed out in the annexed claims.

Thus, slippage is afforded as the tightens the blocks againstfthe Ijclaim as my invention:

1. Ina clutch mechanism, alined driving and vdriven elements, a frictional clutch unit for sesurfaces, said means being forced against the clutch surfaces by the clutch members in the relative shifting thereof toward each other to connect the clutch members and having clutch faces complementary to those of the clutch members, and shifting means. for the clutch members.

2. In a clutch mechanism, alined driving and drivenelements, a frictional clutch unit for selectively connecting said elements, said unit comprising a pair of relatively shiftable co-operating clutch members on the respective elements, said clutch members having annular frictional clutch surfaces at different angles to the axis of rotation of the elements and disposed with their apices on the same side of the clutch members, blocks between and engageable with said clutch surfaces, said blocks being forced against the clutch surfaces by the clutch members in the relative shifting thereof towardv each other to .connect the clutch members and having clutch faces complementary to those of the clutch members, means for holding the `blocks between the clutch members, and shifting means for the clutch members.

3. In a clutch mechanism,4 alined driving and driven elements, a frictional clutch unit for selectively connecting said elements. said unit comprising ,a pair of co-operating clutch members on the respective elements, said clutch members having annular frictional clutch surfaces at different angles to the axis of rotation of the elements, blocks between and engageable with said clutch surfaces, said blocks being forced against the clutch surfaces when connecting the clutch members and having clutch faces complementary to those of the clutch members, and a carrier for holding the blocks between the clutch members and having openings therein to accommodate the blocks.

. 4. In a clutch mechanism, alined driving and driven elements, a frictional clutch unit for se lectively connecting said elements, said unit comprising a pair of co-operating clutch members on the respective elements, said clutch members having annular frictional clutch surfaces at different angles to the axis of rotation of the elements, blocks between and engageable with said clutch surfaces, said blocks being forced against the clutch surfaces when connecting the clutch members and having clutch faces complementary to those of the clutch members, a carrier -for holding the blocks between the clutch members and having openings to accommodate the blocks, and means providing an intertting connection between the openings and the blocks to prevent the blocks dropping out of the openings when one of the clutch membersis out of contact y-with the blocks.

5. In a.- clutch mechanism, aiined driving and driven elements, a frictional clutch unit for selectively connecting said elements, said unit comprising a pairof relatively shiftable clutch membe'r's on the respective elements, said clutch members having annular inclined frictional clutch edgeof the carrier for yieldably urging the same toward the stop.

6. In a rclutch mechanism, alined driving and driven elements, a frictional clutch unit for selectively connecting said elements,` said unit comprising xed and shiftable clutch members on the respective elements, said clutch members having annular inclined clutch surfaces about said elements, blocks between and complementary to said surfaces, said blocks being forced against the surfaces to connect the clutch members on shifting the shiftable clutch member toward the fixed clutchk member, and means for holding the blocks between the clutch surfaces.

1. In a clutch mechanism, alined drivingA and driven elements, a'frictional clutch unit for selectively' connecting lsaid elements, said unit comprising fixed and shiftable clutch members on the respective elements, said clutch members having annular inclined clutch surfaces about said elements, blocks between and complementary to said surfaces. said blocks being forced against the clutch surfaces to connect the clutch members. on shifting kthe shiftable clutch member toward the fixed clutch member, means for holding the blocks between the clutch surfaces, and means acting to center the blocks between the'clutch surfaces on lthe shifting of lthe shift* able clutch member toward the fixed one.

8. In a Vclutch mechanism, alined driving and driven elements, africtional clutch unit for selectively connecting.4 said elements, said unit" comprising fixed and shiftable clutch members on the respective elements, said clutch members having annular1 inclined clutch surfaces about said elements, blocks between and complementary to said surfaces, said blocks being forced aginst said surfaces to ,connect the clutchr members on shifting: the shiftable clutch member toward the fixed clutch member, a carrier between the surfaces for the blocks, and means acting on the carrier in the movement of the shiftable clutch member toward the fixed clutch member to center the carrier and the blocks with respect to the clutch surfaces.

9. In a clutch mechanism, alined driving and driven elements, a frictional clutch unit for selectively connecting said elements, said unit comprising fixed and shiftable clutch members on they respective elements, said clutch members having annular'inclined clutch surfaces about said elements, blocks between and cmplemen tary to said surfaces, said blocks being forced against the clutchsu'rfaces to connect the clutch members on shifting the shiftable clutch memr ber toward the fixed clutch member, a carrier between the clutch surfaces for the blocks, and means on the shiftable clutch member andengageable with the carrier in the shifting of said clutch member toward the fixed one to engage the carrier to center the same and the blocks with respect to clutch surfaces.

10. In a clutch mechanism, aiined driving and driven elements, a frictional clutch unit and a positive clutchunt for said elements, means for actuating said units to connect the elements rst through the frctional clutch andlater through the positive clutch, and means providing the me;

` tional clutch unit with co-operatlng annular frictional clutchr surfaces surrounding said elements `and disposed' at different angles tothe axis of rotation thereof to afford a driving connection for the frictional clutch through. the

clutch ksurface'of the lesser angle and a quick release for the frictional clutch through the `clutch surface of the greater angle whereby the positive clutch unit mayk connect the elements on the de-clutching of the frictionalclutch kwithout an appreciable lossof synchronism between the elements as established by the frictional clutch. a

11. In aclutch mechanism, alined driving and driven elements, a frictional clutch unit and a positive clutch unit for said elements, means for actuating said units to connect the elements rst through the frictional kclutch and later through the positive clutch, said frictlonal clutch unitrhaving annulark frictional clutch `surfaces and an interposed means engageable with and complementary to the clutch surfaces of the frictional clutch unit, said means being forced kagainstsaid clutchsurfaces when connecting rthe driving connection for the frictional clutch through the clutch surface of the lesserangle and a quick release for said clutch through the clutch surface of the greater angle whereby the positive clutch unit on the de-clutching of the frictional clutch may connect the elements withoutr an appreciable loss of synchronism between ythem,asiestablished yby the frictional clutch. j i

12. In a clutch mechanism, alin'ed spllned driving and driven elements, a frictional clutchr unit and a positive clutchy unit for said elements, means for actuating said units to connect the 'elements first through the frictional clutch and later through the vpositive clutch, said units having relatively shiftable clutch members on the respective elements, the positive clutch mem ber being shiftable into bridging relation with the adjacent ends of the elements and engaging the splines thereof `for connecting `the elementsy through rthe positiveclutch on the de-l'clut'ching of the frictional clutch, the latter having annuc lar inclined frictional clutch surfaces about said elements and disposed at different angles to the axis of rotation thereof to afford by the lesserl angle a driving connection for the frictional clutch and by the greater angle a quick release vfor the' frictional clutch on beingdisengaged whereby the positive clutch member maybe readily and easily engaged with the splines of the co-operating element withouty an appreciable loss of synchronism ybetween the elements as established by the frictional clutch. n

13. A frictional clutch unit of the character described, comprising a pair of relativelyshiftable yco-operating clutch members adapted for rotation about a common axis, said clutch members having frictional clutch surfaces about said axis and r'disposed at different angles thereto with their apices on the same side ofthe clutch members to, afford by the surface of the lesser angle a driving connection for the clutch unit when engaged and by the surface of the greater angle aquick release for the clutch unit on being disengaged, means for establishing an operative connection between said clutch surfaes on the engagement of the unit, said means being kforced into engagement with said y.clutch surfaces by the clutch members in the relative shifting thereof towardv each other, and shifting means for said clutch members.

14. A frictional clutch -unit of the character described, comprising a pair of relatively shiftable co-operating clutch members adapted for rotation about a common axis, said clutch members having frictional clutch surfaces about said axis and disposed at different angles thereto with their apices on the same side of the clutch members to afford by the surface of the lesser angle a driving connection forthe clutch unit 'when engaged and by the surface of the greater angle a quick release for the unit on being disengaged, blocks between and engageable with said clutch surfaces, said blocks being complementary' to said clutch surfaces and forced against the clutch clutch surfaces about said axis, clutching means movably mounted in the space between said inclined clutch surfaces and having frictional clutch surfaces complementaryA to and engageable with the inclined clutch vvsurfaces of the clutch members, said clutching means connecting the clutch members on being clamped between the inclined clutch surfaces thereof in the relative shifting of the clutch members toward each other to close the clutch unit, and means acting on said clutching means'to position the latter to be properly clamped between the clutch members. i

16. In a clutch mechanism,- alined driving and driven elements, a frictional clutch unit and a positive clutch unit for said elements, means for actuating said units to connect the elements first through the frictional clutch and later through .the positive clutch, said frictional clutch unit having relatively shiftable clutch members on the respective elements and provided With radially spaced inclined clutch surfaces about said elements, and clutching meansmovably mounted in the space between said inclined clutch surfaces and having frictional clutch surfaces complementary to and engageable therewith, said clutch means connecting said clutch members on being clamped between the inclined clutch surfaces thereof in the relative 4shifting of the clutch members toward each other to close the frictional clutch unit, and said positive clutch unit having means co-operating Withthe frictional clutch members to .positively connect the elements on their release by the frictional clutch members following the establishment 'of synchronization between the elements by'the frictional clutch.

17. In a clutch mechanism, the combination of driving and driven members, connecting means therefor for selectively connecting said driving and driven members, said connecting means including means spaced from said driving and driven members, and a clutch member adapted to selectively engage and be disengaged from said driving and driven members, said member having surfaces engageable respectively with said driving and driven members, the elements forming said surfaces being unbroken straight lines, coplanar elements in different surfaces being disposed at an angle to each other,

said connecting means when; inoperative to 'connect said driving and driven members being relatively movable Vwith respect vto said driving and f" driven members. .l i

18. In clutch mechanism, the combination of driving and driven members, connecting means therefor for selectivelpy connecting said driving and driven members, said connecting -means including means spaced from said driving and driven members, and a clutch member adapted to selectively engage and be disengaged from said driving and driven members, said member having surfaces' engageable vrespectively with said driving and vdriven members,- coplanar elements forming said surfaces being divergent and forming unbroken contact surfaces, said con-- necting means when inoperative to connect said.

driving and driven members being relatively Y movable with respect to said driving and-driven members.

19. In clutch mechanism,v the combination of driving and driven members, connecting means therefor for selectively connecting said .driving and driven members, ksaid connecting means including means spacedY from said driving and driven members, and a-clutch member adapted to selectively engage and be disengaged from said driving and driven members, said member having surfaces engageable respectively with said driving and driven members, the elements forming said surfaces being unbroken straight lines,`

coplanar elements in different surfacesbeing dis posed at an angle to each other, said connectings means wheninoperative to connect said driving and driven members being relatively movable with respect to said driving and driven' members,v the surfaces ofv said drivingand drivenmembers contacting said surfaces of said clutch member being substantially complementary and parallel thereto.

20. In clutch mechanism, the combination of driving and driven members, connecting means therefor for selectivelyv connecting said driving and driven members, said connectingmeans including means spaced fromsaid driving and driven members, and a clutch member adapted,-

to selectively engage' and be disengaged. from said driving and-driven members, said member having surfaces engageable respectively with said driving and driven members, coplanar elements forming said surfaces beingdivergent and forming unbroken contact surfaces, said connectingl means when inoperative to connect said driving and driven members being vrelatively .movable v55 with respect to said driving and driven inembers, the surfaces of said driving and driven members contacting said surfaces of said clutch member -being substantially complementary and parallel thereto.

21. In a clutch mechanism, driving and driven elements, a frictional clutch unit for selectively connecting said elements, said unit comprising a pair of relatively shiftable cooperating clutch members on the respective elements, said clutch members each having an annular frictional clutch surface disposed at an angle to each other, blocks between and engageable with said clutch surfaces, said blocks being forced vagainst the clutch surfaces by the clutch members in the relative shifting thereof toward each other .to

connect the clutch members and having clutch 22. In a` clutch mechanism, driving and driven elements, a frictional clutch unit for selectively connecting said elements, said unit comprising a pair of relatively shiftable cooperating clutch members on the respective elements, said clutch members each having an annular frictional clutch surface disposed at an angle to each other, blocks between and engageable with said clutch surfaces, said blocks being forced against the clutch surfaces by the clutch members in the relative shifting thereof toward each other to connect the clutch members and having clutch faces complementary to those of the clutch members, means for holding the blocks between the clutch surfaces, and shifting means for said clutch members.

23. In a clutch mechanism, driving and driven elements, a frictional clutch unit for selectively connecting saidelements, said unit comprising a pair of cooperating clutch members on the respective elements. said clutch members each having an annular frictional clutch surface disposed at an angle to each other, blocks between and engageable with said clutch surfaces, said blocks being forcedagainst the clutch surfaces when connecting the clutch members and having clutch faces complementary to those of the clutch members, said blocks being relatively movable with respect to said clutch members when in position to disconnect said clutch members.

24. In a clutch mechanism, driving and driven elements, a frictional clutch unit for selectively connecting said elements, said unitcomprising a pair of cooperating clutch members'on the respective elements, said clutch members each having an annular frictional clutch surface disposed at an angle to each other, blocks between and engageable with said clutch surfaces, said blocks being forced against the clutch surfaces when connecting the clutch members and having clutch faces complementary to those of the clutch members, said blocks being relatively movable with respect to said clutch members when in position to disconnect said clutch members, and means for holding the blocks between the clutch surfaces.

25. In clutch mechanism, the combination of driving andy driven members, connecting means therefor for selectively connecting said driving and driven members, said connecting means including engage and are disengaged from said driving and driven members when said driving and driven members are connected and disconnected, said connecting means when inoperative to connect said driving and driven members being relatively f movable with respect to said driving and driven members.

26. In a clutch mechanism, the combination of cooperating clutch members adapted for rotation about a common axis, said clutch members having frictional clutch surfaces disposed at different angles. and clutching means interposed between said clutch surfaces and selectively en gageable therewith for clutching and declutchng said clutch members, said clutching. means having frictional clutch surfaces engageable with and complementary to the clutch surfaces of the clutch members, said clutching means being forced against the clutch surfaces of the clutch members when connecting the clutch members and when inoperative vto connect said clutch members being relatively movable with respect thereto. ,y n

27. In a clutch mechanism, the combination of cooperating clutch members adapted for rotation about a common axis, said clutch members having radially spaced inclined frictional clutch surfaces disposed at different angles tovk each other, and clutching means interposed between said in'- clined clutch surfaces and selectively engageable therewith for clutching and declutching said' clutch members, said clutching means having frictional clutch surfaces engageable with and complementary to the clutch surfaces ot the clutch members, said clutchingmeans being forced against the clutch members and when inoperative to connect said clutch members being relatively movable with respect thereto.

LEON J. CAIPBELL. 

